Ergot poisoning: the original Purple Haze

Detail of The Temptations of St. Anthony by Matthias Grünewald, c. 1512-15

Detail from The Temptations of St. Anthony by Matthias Grünewald, c. 1512-15

“[A] Great plague of swollen blisters consumed the people by a loathsome rot, so that their limbs were loosened and fell off before death.”  From the Annales Xantenses (857 AD).


It has been blamed for the Salem witch trials and the “Great Fear” of 1789,  which contributed to the French Revolution.  Its reemergence in the 20th century led to a treatment for migraine headaches and to the invention of LSD.

But in the Middle Ages, what we now call ergot poisoning, or ergotism, was a terrifying mystery known as “Holy Fire” (ignis sacer) because of the terrible burning pain it caused. Ergot — the common name for Claviceps purpurea – is a fungus that affects rye and other grains.  It contains ergotamine which, in moderate doses, causes the contraction of smooth muscle fibers, such as those in the small arteries.

In higher doses, however, ergot can cause diarrhea, nausea and vomiting, followed by headaches, vertigo, painful muscle spasms, convulsions, seizures and even death.  Hallucinations are often of demons or animals, as well as the sensation of itching or burning.  The sufferer may believe he is crawling with insects or engulfed in flames.

Worse, ergot also causes dry gangrene, the result of restricted blood flow to the extremities.  Symptoms of dry gangrene include peeling skin, swelling, and loss of feeling in the fingers and toes.  The infected tissues can even die and fall off.


References to the affliction date from as far back as the 7th century AD.  But the first full description we have comes from an outbreak in 944, in which 40,000 people in southern France died after suffering agonizing convulsions, hallucinations, and loss of limbs.

The first effective treatments for ergot poisoning came after the Order of Hospitallers of St. Anthony was founded near Grenoble, France in 1093.  People visiting the order seemed to get better, and the afflicted began to flock there in such great numbers that the condition soon became known as Saint Anthony’s Fire.

Anthony himself was a third century ascetic from Egypt, who suffered from visions in which he battled against the devil.  His ordeal has become a popular subject in literature and art, best known from paintings by Matthias Grunewald, Max Ernst, Salvador Dali, and Hiëronymus Bosch, who placed a severed foot among the unfortunates in his triptych “The Temptation of St. Anthony.”

Center panel from the triptych The Temptation of St. Anthony by Hieronymous Bosch, painted c. 1501

Center panel from the triptych The Temptation of St. Anthony by Hieronymous Bosch, painted c. 1501

Although ergot infects several types of grain, most outbreaks of ergot poisoning occur from the ingestion of rye.  This is because ergot appears as purple spurs, which can easily be seen on light-colored grains such as wheat and barley.  It is, however, much harder to detect it on rye, especially after the grain has been milled into flour.  To French farmers in the Middle Ages, the fungus looked like a rooster’s spur. Hence they called it argot, which means “cockspur” in French.

Ergot fungus "spurs" in a head of grain.

Ergot fungus “spurs” in a head of grain.

In 1670, a French physician, Dr. Thuillier, noticed that St. Anthony’s Fire seldom afflicted the rich, who ate more meat.  He deduced that the condition might be caused by something in the diet.  But although ergot had been observed on grain for a long time, it had generally been considered harmless.  It would take another 200 years before Louis Tulasne, an early mycologist (a biologist who deals with fungi), realized that the fungus, and not the rye itself, was responsible for St. Anthony’s Fire.

The discovery that ergot caused St. Anthony’s Fire led to enhanced scrutiny and conditions for storing grain and to a great degree helped control the disease.  In 1951, however, an outbreak in Pont-Saint-Esprit, France led to dire consequences. A 68-year-old woman threw herself from a third-floor window to escape what she thought were flames enveloping her.  A man barricaded himself inside his home with a gun to shoot the monster that was stalking him.  Still another man was heard to scream, “My head is on fire! There are snakes in my belly!” before attempting to throw himself into the Rhone.  Two hundred or so people became ill.  Of these, some two dozen were placed in straitjackets and institutionalized.  Four people died.

Like many poisons, ergot in small doses can be beneficial.  For centuries, midwives had used it to promote contraction of the uterus (and hence childbirth) in women experiencing long labor.  In the early 20th century, Sandoz Pharmaceuticals isolated the ergotamine in ergot and formulated medicines to control postpartum bleeding and to treat migraines.

And in the 1930s, a chemist named Albert Hofmann experimented with the alkaloids in ergot and discovered a new compound: lysergic acid diethylamide, or LSD. 


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